Management of Hypertension M Misra MD MRCP (UK) Division of Nephrology University of Missouri School of Medicine
Disturbing Trends in Hypertension HTN awareness, treatment and control rates are decreasing Age adjusted mortality rates for stroke and CHD appear to be either rising or leveling of The incidence of ESRD and the prevalence of CHF is increasing HTN related complications are a public health concern Treatment of HTN is a worldwide failure!
Mechanics of Hypertension Primary salt factor: suppressed renin good response to a diuretic Primary Renin Angiotensin factor: elevated renin good response to antirenin-angiotensin angiotensin type medication
Blood Pressure and Cardiovascular Risk Relationship between BP and Cardiovascular risk Strong Continuous Graded Consistent Independent Predictive Etiologically significant
Why treat? Hypertension is deleterious to the vascular health Evidence from natural experiments in humans: Unilateral RVD Coarctation of aorta Pulmonary hypertension Evidence from animal experiments Evidence from Clinical trials
Variables in Treatment and/or Response Race / ethnicity Age Sex Co-morbidity Co-treatment
Management Objectives Identify Cause Identify other Cardiovascular Risk Factors Assess Target Organ Damage Assess Cardiovascular Disease.
Classification of Hypertension in adults (>18years)
Identifiable causes of Hypertension Sleep Apnea Drug induced/related Chronic Kidney Disease Primary aldosteronism Renovascular disease Cushings/chronic steroid therapy Pheochromocytoma Coarctation of aorta Thyroid or hyperparathyroid disease
Lifestyle modifications for Hypertension
Renal Diseases in Hypertension Core Concepts of Treatment Hypertension is an independent variable that predicts long-term decline in renal function Proteinuria is also an independent variable that predicts long-term decline in renal function Reduction of blood pressure reduces both cardiovascular and renal risk Reduction of proteinuria may reduce both cardiovascular and renal risk Relative renal hypoperfusion during initial stages of therapy for hypertension is associated with a transient limited rise in serum creatinine and is not a reason to stop therapy
The Dual Significance of Proteinuria Proteinuria (albuminuria( albuminuria) ) results from injury to glomerular circulation Increased proteinuria (albuminuria( albuminuria) ) is associated with progressive kidney disease In diabetes and hypertension, proteinuria (albuminuria)) is also an indicator of injury in the systemic circulation Proteinuria (albuminuria( albuminuria) ) is associated with increased cardiovascular risk
Definitions of Microalbuminuria and Macroalbuminuria Parameter Normal Micro- albuminuria Macro- albuminuria Urine AER (μg/min) Urine AER (mg/24h) Urine albumin/ Cr # ratio (mg/gm) < 20 20-200 >200 < 30 30-300 >300 < 30 30-300 >300 AER=Albumin excretion rate CR # =creatinine
Goal BP Recommendations for Patients with DM or Renal Disease Organization American Diabetes Association 2001 Systolic Year BP Diastolic BP National Kidney Foundation 2000 <130 <80 Canadian Hypertension Society 1999 <130 <80 British Hypertension Society 1999 <140 <80 WHO & International Society of Hypertension Joint National Committee (JNC VI) 1999 1997 <130 <80 <130 <85 <130 <85
Drug Therapy Avoid overdosing Avoid Quick Fix (cerebral and coronary hypoperfusion may result) Aim for 24 hour coverage
Drug Therapy Minimize Side Effects Establish goal Educate Maintain contact Keep care inexpensive Favor longer acting medications Be willing to change
Blood Pressure * = non-dihydropyridine CCBs Anti-Hypertensive Drugs: Sites of Action Cardiac Output = X β- Blockers CCBs * Diuretics Total Peripheral Resistance ACE Inhibitors AT 1 Blockers a-blockers a 2 -Agonists CCBs Diuretics Sympatholytics Vasodilators
Average Number of Anti-Hypertensive Agents Used to Achieve Target BP Goal BP MDRD <92 mmhg MAP* ABCD <75 mmhg DBP HOT <80 mmhg DBP UKPDS <85 mmhg DBP Achieved BP 93 ~75 81 82 Avg # of drugs per patient 3.6 2.7 3.3 2.8 *The goal mean arterial pressure (MAP) of <92 mmhg specified in the MDRD trial corresponds to a systolic/diastolic blood pressure of approximately 125/75 mmhg.
Diuretics Action: : Decrease plasma volume and TPR. Effect: : Decrease D overall CV mortality. Side effects: : Mainly metabolic Start with a thiazide diuretic (low dose combinations) Loop diuretics required if serum Cr > 2.5 mg/dl
β Blockers Reduce CO, Sympathetic outflow, Renin release Indications: Young, Middle aged, Caucasian Post MI Increased level of stress Lipid solubility Cardio-selectivity Intrinsic sympathomimetic activity
Calcium Channel Blockers Dihydropyridines : vasodilators Short acting CCB are contraindicated Post MI HT emergencies Non dihydropyridines: Depress cardiac contractility Inhibit AV node Induce vasodilatation. Elderly and Black patients respond better
ACE inhibitors Main action is to block conversion of ATI to ATII Protect the heart and the kidneys Diuretics enhance ACEI response Use with caution in Renovascular HTN Hyperkalemia and Cough are common Contraindicated in Pregnancy
Inadequate Response Pseudo-resistance Non adherence Volume overload Drug Related Causes/Interactions (NSAIDS, Cyclosporin, Epogen, Cold remedies, Caffeine, Cocaine) Associated Conditions (Smoking, Obesity, Alcohol, OSA, Chronic pain) Secondary Causes
Case 1 65 y/o m with 20 y h/o mild HTN. BP was well controlled with medications that were discontinued after Cardiac Cath for Angina. BP gradually drifted up in the next 1-21 2 years. Patient was started on ACEI with a sharp fall in BP, and a rise in S Cr. from 2 to 6.0 mg/dl. What is the mechanism of HTN? Why did renal function deteriorate? What alternative therapies are available?
Clinical clues of Renovascular Disease Age of Onset Abdominal Bruit Accelerated or resistant Hypertension Flash Pulmonary Edema Renal Failure of uncertain etiology Widespread Vascular disease ARF precipitated by ACEI Asymmetric Kidneys
Hypertension & Diabetes Mellitus Measure BP in all 3 positions Aim for 125/75 mm Hg Preferably use ACEI, ARB Supplement Treatment with life style modifications
HTN and Renal Parenchymal Disease HT nephrosclerosis is a very common cause of CKD in African Americans Aim for 130/80 or lower especially in those with proteinuria Adequate control is more important than type of therapy
Case 2 82 y/o male with long standing systolic HTN. BP is recorded at 220/70 mm Hg. What is the mechanism of Hypertension? Is there value of lowering BP in this individual? What agents would you consider as initial therapy?
Hypertension in the elderly Extremely common in older Americans Elevated SBP and/or Pulse Pressure is a better adverse event predictor in this age group Primary HTN is the commonest etiology. Pseudo HTN and White coat HTN is common Orthostatic Hypotension is commoner
Hypertension in the elderly Should we treat? What is the goal BP? What medications to use?
Should we Treat Hypertension in the elderly? Treatment reduces CVD/CHD morbidity and mortality Any reduction in BP confers benefit The closer to normal blood pressure, the greater the benefit
What medications? For Isolated SHTN use Diuretics Calcium channel blockers β blockers and ACEI may be added if needed
GOAL BP in Elderly DBP <85-90 and SBP <160 (if initial SBP>180) or 20mm below baseline if initial SBP was between 160-180 180
Management of hypertension Key points Risk Stratify Try Life Style Modifications Individualize Drug therapy
Management of Hypertension Key points Try once daily drugs or pharmacologically complementary combinations Apply redefined targets for special subsets of patients Try once daily drugs or pharmacologically complementary combinations in the elderly.
The overriding issue Lower the Blood Pressure to maximally reduce cardiovascular risk without decreasing and perhaps even improving the enjoyment of life!